1. Field of the Invention
Embodiments of the present invention relate to a control apparatus for a hybrid vehicle that allows automatic operation.
2. Description of the Related Art
For this type of apparatus, there is known an apparatus configured to determine an optimal running mode in a hybrid vehicle in automatic operation. For example, Japanese Patent Application Laid Open No. 2013-001214 discloses an apparatus configured to determine whether or not to start an internal combustion engine (i.e. whether to operate the internal combustion engine to run in a HV mode, or to stop the internal combustion engine to run in an EV mode), on the basis of an amount of energy required from a current place to a destination.
A driver sometimes does not want to start the internal combustion engine (i.e. wants to keep running in the EV mode with the internal combustion engine stopped) depending on a surrounding environment of the vehicle. Most drivers do not want to start the internal combustion engine in order to avoid making an operation sound of the internal combustion engine, for example, if there are pedestrians in the surroundings of the vehicle, if the vehicle runs at a low speed around the driver's house in the middle of the night, if the vehicle runs in a building, or in similar cases.
If the vehicle performs the automatic operation, however, the internal combustion engine is sometimes automatically started, depending on a running condition of the vehicle or the like. Thus, even if the driver does not want to start the internal combustion engine, there is a possibility that the internal combustion engine is started against the driver's intention. Such a situation is not preferable from the viewpoint of drivability and from the viewpoint of noise to the surroundings.